The present invention relates generally to fiber optic interfaces, and more particularly, a fiber optic interface that may be employed with a computer system to provide a direct interface between the computer system and an image storage system coupled to the computer by way of optical cables.
In an image distribution system comprising a plurality of imaging consoles or computer workstations, it is generally required that images be distributed rapidly. Otherwise an operator using an imaging console has to wait long periods for images to appear on a display monitor. If the wait is too long, the operator may opt to use film instead of the imaging console. Film has a large effective image capacity, but is expensive, and it is clumsy to use, requiring chemicals to produce the images and large storage areas for retention of historical images. A high speed interface between an image storage device and image workstations has been used using copper cables. However, the length of the copper cables is very limited. Typical lengths for a 10 megabit per second data transfer rate are less than 100 feet. When the data rate is higher than 10 megabit per second or the distance is longer than 100 feet, another technique is necessary. A fiber optic relay may provide a high speed serial data path from the image storage device to a computer workstation.
The data transfer rates over a fiber optic link using inexpensive transmitters and receivers can be several kilometers. The conventional approach is to build the image storage device with a copper cable interface to a fiber optic interface where the data is transformed from parallel to serial form and then sent out to the image workstations at high data transfer rates, typically on the order of 100 megabits per second. The length of the copper cable is relatively short, since the transformation to the fiber optic cable can be close to the image storage unit. At the image workstation, there is a fiber optic receiver that converts the optical signal transmitted over the fiber back to an electrical signal suitable for transmission over a copper cable that ultimately connects to the image workstation. With this approach, however, there is a small external interface box that is attached to each image workstation. The external interface box provides the means for providing signal transformation from the optical fiber to the copper cable.
However, if the interface transformer from fiber to cable could be eliminated, the image workstation would be much simpler. The image workstations are the most numerous component in the system. Any simplification of the workstation reduces the cost of the total system in proportion to the level of the simplification. In a typical system, there are only one or two central optical storage units, or archive optical systems, and several host computers. When there are many (100 ) workstations, for example, a reduction of 10% in the cost of a workstation will have a dramatic effect on the overall cost of the system.
Therefore, it is an objective of the present invention to provide for a fiber optic interface that may be employed with a computer system to provide a direct interface between the computer system and an image storage device coupled to the computer by way of optical cables.